1. Field of the Invention
The present invention relates to a process for producing a perovskite-type oxide catalyst useful in the catalytic combustion of combustible gases such as hydrogen, carbon monoxide or hydrocarbons.
2. Description of the Prior Art
Since perovskite-type oxides (ABX.sub.3 type) are very stable, it is possible to form catalytically active sites, such as defects while maintaining the crystal structure of the oxides. Therefore, perovskite-type oxides have had great expectations as oxidizing catalysts.
In known production processes of perovskite-type oxide catalysts, a firing of the raw materials at high temperatures is needed. However, this high temperature firing causes an unfavorable grain growth of the resultant catalyst, and reduces the catalytically active sites. Consequently, a sufficiently high catalytic activity can not be obtained.